Personal and home computers have found many uses. One of these uses is to have a computer synthesize music. Thus, a computer can have a sound interface chip to create sounds which are heard through the monitor speaker (or the speakers of a stereo system). The computer can be programmed such that selected computer keyboard keys will correspond to desired sounds. By depressing the selected keys in a particular order, music can be created or composed. However, the educational and entertainment values of this use for a computer have been limited. Using a computer keyboard to simulate or teach the playing of a musical instrument, such as a piano, is simply not realistic. One does not get the feel of the instrument or readily transferable experience of playing the instrument.
Auxilliary keyboard devices have been developed for various purposes. U.S. Pat. No. 4,119,839 to Beckmann et al describes a keyboard mask for a calculator which limits accessibility of the calculator keyboard to a selected group of keys. U.S. Pat. No. 3,825,101 to Wineman discloses an auxilliary keyboard device for a typewriter adapted to provide a 10-key format for the numeral keys of the typewriter. The device uses motion transfer bars to couple certain of its keys to corresponding laterally spaced typewriter keys. It is also known to have an overlay for a computer keyboard having cutouts for the keys of the keyboard. On the overlay is printed information about the functions of the various keys. However, none of these devices relates to converting a computer keyboard format to simulate a musical instrument.